diff options
Diffstat (limited to 'kernel/arch/arm/mach-vexpress/spc.c')
| -rw-r--r-- | kernel/arch/arm/mach-vexpress/spc.c | 592 |
1 files changed, 592 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-vexpress/spc.c b/kernel/arch/arm/mach-vexpress/spc.c new file mode 100644 index 000000000..f61158c6c --- /dev/null +++ b/kernel/arch/arm/mach-vexpress/spc.c @@ -0,0 +1,592 @@ +/* + * Versatile Express Serial Power Controller (SPC) support + * + * Copyright (C) 2013 ARM Ltd. + * + * Authors: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> + * Achin Gupta <achin.gupta@arm.com> + * Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> + * + * 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 "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. + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/cpu.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> +#include <linux/slab.h> +#include <linux/semaphore.h> + +#include <asm/cacheflush.h> + +#define SPCLOG "vexpress-spc: " + +#define PERF_LVL_A15 0x00 +#define PERF_REQ_A15 0x04 +#define PERF_LVL_A7 0x08 +#define PERF_REQ_A7 0x0c +#define COMMS 0x10 +#define COMMS_REQ 0x14 +#define PWC_STATUS 0x18 +#define PWC_FLAG 0x1c + +/* SPC wake-up IRQs status and mask */ +#define WAKE_INT_MASK 0x24 +#define WAKE_INT_RAW 0x28 +#define WAKE_INT_STAT 0x2c +/* SPC power down registers */ +#define A15_PWRDN_EN 0x30 +#define A7_PWRDN_EN 0x34 +/* SPC per-CPU mailboxes */ +#define A15_BX_ADDR0 0x68 +#define A7_BX_ADDR0 0x78 + +/* SPC CPU/cluster reset statue */ +#define STANDBYWFI_STAT 0x3c +#define STANDBYWFI_STAT_A15_CPU_MASK(cpu) (1 << (cpu)) +#define STANDBYWFI_STAT_A7_CPU_MASK(cpu) (1 << (3 + (cpu))) + +/* SPC system config interface registers */ +#define SYSCFG_WDATA 0x70 +#define SYSCFG_RDATA 0x74 + +/* A15/A7 OPP virtual register base */ +#define A15_PERFVAL_BASE 0xC10 +#define A7_PERFVAL_BASE 0xC30 + +/* Config interface control bits */ +#define SYSCFG_START (1 << 31) +#define SYSCFG_SCC (6 << 20) +#define SYSCFG_STAT (14 << 20) + +/* wake-up interrupt masks */ +#define GBL_WAKEUP_INT_MSK (0x3 << 10) + +/* TC2 static dual-cluster configuration */ +#define MAX_CLUSTERS 2 + +/* + * Even though the SPC takes max 3-5 ms to complete any OPP/COMMS + * operation, the operation could start just before jiffie is about + * to be incremented. So setting timeout value of 20ms = 2jiffies@100Hz + */ +#define TIMEOUT_US 20000 + +#define MAX_OPPS 8 +#define CA15_DVFS 0 +#define CA7_DVFS 1 +#define SPC_SYS_CFG 2 +#define STAT_COMPLETE(type) ((1 << 0) << (type << 2)) +#define STAT_ERR(type) ((1 << 1) << (type << 2)) +#define RESPONSE_MASK(type) (STAT_COMPLETE(type) | STAT_ERR(type)) + +struct ve_spc_opp { + unsigned long freq; + unsigned long u_volt; +}; + +struct ve_spc_drvdata { + void __iomem *baseaddr; + /* + * A15s cluster identifier + * It corresponds to A15 processors MPIDR[15:8] bitfield + */ + u32 a15_clusid; + uint32_t cur_rsp_mask; + uint32_t cur_rsp_stat; + struct semaphore sem; + struct completion done; + struct ve_spc_opp *opps[MAX_CLUSTERS]; + int num_opps[MAX_CLUSTERS]; +}; + +static struct ve_spc_drvdata *info; + +static inline bool cluster_is_a15(u32 cluster) +{ + return cluster == info->a15_clusid; +} + +/** + * ve_spc_global_wakeup_irq() + * + * Function to set/clear global wakeup IRQs. Not protected by locking since + * it might be used in code paths where normal cacheable locks are not + * working. Locking must be provided by the caller to ensure atomicity. + * + * @set: if true, global wake-up IRQs are set, if false they are cleared + */ +void ve_spc_global_wakeup_irq(bool set) +{ + u32 reg; + + reg = readl_relaxed(info->baseaddr + WAKE_INT_MASK); + + if (set) + reg |= GBL_WAKEUP_INT_MSK; + else + reg &= ~GBL_WAKEUP_INT_MSK; + + writel_relaxed(reg, info->baseaddr + WAKE_INT_MASK); +} + +/** + * ve_spc_cpu_wakeup_irq() + * + * Function to set/clear per-CPU wake-up IRQs. Not protected by locking since + * it might be used in code paths where normal cacheable locks are not + * working. Locking must be provided by the caller to ensure atomicity. + * + * @cluster: mpidr[15:8] bitfield describing cluster affinity level + * @cpu: mpidr[7:0] bitfield describing cpu affinity level + * @set: if true, wake-up IRQs are set, if false they are cleared + */ +void ve_spc_cpu_wakeup_irq(u32 cluster, u32 cpu, bool set) +{ + u32 mask, reg; + + if (cluster >= MAX_CLUSTERS) + return; + + mask = 1 << cpu; + + if (!cluster_is_a15(cluster)) + mask <<= 4; + + reg = readl_relaxed(info->baseaddr + WAKE_INT_MASK); + + if (set) + reg |= mask; + else + reg &= ~mask; + + writel_relaxed(reg, info->baseaddr + WAKE_INT_MASK); +} + +/** + * ve_spc_set_resume_addr() - set the jump address used for warm boot + * + * @cluster: mpidr[15:8] bitfield describing cluster affinity level + * @cpu: mpidr[7:0] bitfield describing cpu affinity level + * @addr: physical resume address + */ +void ve_spc_set_resume_addr(u32 cluster, u32 cpu, u32 addr) +{ + void __iomem *baseaddr; + + if (cluster >= MAX_CLUSTERS) + return; + + if (cluster_is_a15(cluster)) + baseaddr = info->baseaddr + A15_BX_ADDR0 + (cpu << 2); + else + baseaddr = info->baseaddr + A7_BX_ADDR0 + (cpu << 2); + + writel_relaxed(addr, baseaddr); +} + +/** + * ve_spc_powerdown() + * + * Function to enable/disable cluster powerdown. Not protected by locking + * since it might be used in code paths where normal cacheable locks are not + * working. Locking must be provided by the caller to ensure atomicity. + * + * @cluster: mpidr[15:8] bitfield describing cluster affinity level + * @enable: if true enables powerdown, if false disables it + */ +void ve_spc_powerdown(u32 cluster, bool enable) +{ + u32 pwdrn_reg; + + if (cluster >= MAX_CLUSTERS) + return; + + pwdrn_reg = cluster_is_a15(cluster) ? A15_PWRDN_EN : A7_PWRDN_EN; + writel_relaxed(enable, info->baseaddr + pwdrn_reg); +} + +static u32 standbywfi_cpu_mask(u32 cpu, u32 cluster) +{ + return cluster_is_a15(cluster) ? + STANDBYWFI_STAT_A15_CPU_MASK(cpu) + : STANDBYWFI_STAT_A7_CPU_MASK(cpu); +} + +/** + * ve_spc_cpu_in_wfi(u32 cpu, u32 cluster) + * + * @cpu: mpidr[7:0] bitfield describing CPU affinity level within cluster + * @cluster: mpidr[15:8] bitfield describing cluster affinity level + * + * @return: non-zero if and only if the specified CPU is in WFI + * + * Take care when interpreting the result of this function: a CPU might + * be in WFI temporarily due to idle, and is not necessarily safely + * parked. + */ +int ve_spc_cpu_in_wfi(u32 cpu, u32 cluster) +{ + int ret; + u32 mask = standbywfi_cpu_mask(cpu, cluster); + + if (cluster >= MAX_CLUSTERS) + return 1; + + ret = readl_relaxed(info->baseaddr + STANDBYWFI_STAT); + + pr_debug("%s: PCFGREG[0x%X] = 0x%08X, mask = 0x%X\n", + __func__, STANDBYWFI_STAT, ret, mask); + + return ret & mask; +} + +static int ve_spc_get_performance(int cluster, u32 *freq) +{ + struct ve_spc_opp *opps = info->opps[cluster]; + u32 perf_cfg_reg = 0; + u32 perf; + + perf_cfg_reg = cluster_is_a15(cluster) ? PERF_LVL_A15 : PERF_LVL_A7; + + perf = readl_relaxed(info->baseaddr + perf_cfg_reg); + if (perf >= info->num_opps[cluster]) + return -EINVAL; + + opps += perf; + *freq = opps->freq; + + return 0; +} + +/* find closest match to given frequency in OPP table */ +static int ve_spc_round_performance(int cluster, u32 freq) +{ + int idx, max_opp = info->num_opps[cluster]; + struct ve_spc_opp *opps = info->opps[cluster]; + u32 fmin = 0, fmax = ~0, ftmp; + + freq /= 1000; /* OPP entries in kHz */ + for (idx = 0; idx < max_opp; idx++, opps++) { + ftmp = opps->freq; + if (ftmp >= freq) { + if (ftmp <= fmax) + fmax = ftmp; + } else { + if (ftmp >= fmin) + fmin = ftmp; + } + } + if (fmax != ~0) + return fmax * 1000; + else + return fmin * 1000; +} + +static int ve_spc_find_performance_index(int cluster, u32 freq) +{ + int idx, max_opp = info->num_opps[cluster]; + struct ve_spc_opp *opps = info->opps[cluster]; + + for (idx = 0; idx < max_opp; idx++, opps++) + if (opps->freq == freq) + break; + return (idx == max_opp) ? -EINVAL : idx; +} + +static int ve_spc_waitforcompletion(int req_type) +{ + int ret = wait_for_completion_interruptible_timeout( + &info->done, usecs_to_jiffies(TIMEOUT_US)); + if (ret == 0) + ret = -ETIMEDOUT; + else if (ret > 0) + ret = info->cur_rsp_stat & STAT_COMPLETE(req_type) ? 0 : -EIO; + return ret; +} + +static int ve_spc_set_performance(int cluster, u32 freq) +{ + u32 perf_cfg_reg, perf_stat_reg; + int ret, perf, req_type; + + if (cluster_is_a15(cluster)) { + req_type = CA15_DVFS; + perf_cfg_reg = PERF_LVL_A15; + perf_stat_reg = PERF_REQ_A15; + } else { + req_type = CA7_DVFS; + perf_cfg_reg = PERF_LVL_A7; + perf_stat_reg = PERF_REQ_A7; + } + + perf = ve_spc_find_performance_index(cluster, freq); + + if (perf < 0) + return perf; + + if (down_timeout(&info->sem, usecs_to_jiffies(TIMEOUT_US))) + return -ETIME; + + init_completion(&info->done); + info->cur_rsp_mask = RESPONSE_MASK(req_type); + + writel(perf, info->baseaddr + perf_cfg_reg); + ret = ve_spc_waitforcompletion(req_type); + + info->cur_rsp_mask = 0; + up(&info->sem); + + return ret; +} + +static int ve_spc_read_sys_cfg(int func, int offset, uint32_t *data) +{ + int ret; + + if (down_timeout(&info->sem, usecs_to_jiffies(TIMEOUT_US))) + return -ETIME; + + init_completion(&info->done); + info->cur_rsp_mask = RESPONSE_MASK(SPC_SYS_CFG); + + /* Set the control value */ + writel(SYSCFG_START | func | offset >> 2, info->baseaddr + COMMS); + ret = ve_spc_waitforcompletion(SPC_SYS_CFG); + + if (ret == 0) + *data = readl(info->baseaddr + SYSCFG_RDATA); + + info->cur_rsp_mask = 0; + up(&info->sem); + + return ret; +} + +static irqreturn_t ve_spc_irq_handler(int irq, void *data) +{ + struct ve_spc_drvdata *drv_data = data; + uint32_t status = readl_relaxed(drv_data->baseaddr + PWC_STATUS); + + if (info->cur_rsp_mask & status) { + info->cur_rsp_stat = status; + complete(&drv_data->done); + } + + return IRQ_HANDLED; +} + +/* + * +--------------------------+ + * | 31 20 | 19 0 | + * +--------------------------+ + * | m_volt | freq(kHz) | + * +--------------------------+ + */ +#define MULT_FACTOR 20 +#define VOLT_SHIFT 20 +#define FREQ_MASK (0xFFFFF) +static int ve_spc_populate_opps(uint32_t cluster) +{ + uint32_t data = 0, off, ret, idx; + struct ve_spc_opp *opps; + + opps = kzalloc(sizeof(*opps) * MAX_OPPS, GFP_KERNEL); + if (!opps) + return -ENOMEM; + + info->opps[cluster] = opps; + + off = cluster_is_a15(cluster) ? A15_PERFVAL_BASE : A7_PERFVAL_BASE; + for (idx = 0; idx < MAX_OPPS; idx++, off += 4, opps++) { + ret = ve_spc_read_sys_cfg(SYSCFG_SCC, off, &data); + if (!ret) { + opps->freq = (data & FREQ_MASK) * MULT_FACTOR; + opps->u_volt = (data >> VOLT_SHIFT) * 1000; + } else { + break; + } + } + info->num_opps[cluster] = idx; + + return ret; +} + +static int ve_init_opp_table(struct device *cpu_dev) +{ + int cluster; + int idx, ret = 0, max_opp; + struct ve_spc_opp *opps; + + cluster = topology_physical_package_id(cpu_dev->id); + cluster = cluster < 0 ? 0 : cluster; + + max_opp = info->num_opps[cluster]; + opps = info->opps[cluster]; + + for (idx = 0; idx < max_opp; idx++, opps++) { + ret = dev_pm_opp_add(cpu_dev, opps->freq * 1000, opps->u_volt); + if (ret) { + dev_warn(cpu_dev, "failed to add opp %lu %lu\n", + opps->freq, opps->u_volt); + return ret; + } + } + return ret; +} + +int __init ve_spc_init(void __iomem *baseaddr, u32 a15_clusid, int irq) +{ + int ret; + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) { + pr_err(SPCLOG "unable to allocate mem\n"); + return -ENOMEM; + } + + info->baseaddr = baseaddr; + info->a15_clusid = a15_clusid; + + if (irq <= 0) { + pr_err(SPCLOG "Invalid IRQ %d\n", irq); + kfree(info); + return -EINVAL; + } + + init_completion(&info->done); + + readl_relaxed(info->baseaddr + PWC_STATUS); + + ret = request_irq(irq, ve_spc_irq_handler, IRQF_TRIGGER_HIGH + | IRQF_ONESHOT, "vexpress-spc", info); + if (ret) { + pr_err(SPCLOG "IRQ %d request failed\n", irq); + kfree(info); + return -ENODEV; + } + + sema_init(&info->sem, 1); + /* + * Multi-cluster systems may need this data when non-coherent, during + * cluster power-up/power-down. Make sure driver info reaches main + * memory. + */ + sync_cache_w(info); + sync_cache_w(&info); + + return 0; +} + +struct clk_spc { + struct clk_hw hw; + int cluster; +}; + +#define to_clk_spc(spc) container_of(spc, struct clk_spc, hw) +static unsigned long spc_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_spc *spc = to_clk_spc(hw); + u32 freq; + + if (ve_spc_get_performance(spc->cluster, &freq)) + return -EIO; + + return freq * 1000; +} + +static long spc_round_rate(struct clk_hw *hw, unsigned long drate, + unsigned long *parent_rate) +{ + struct clk_spc *spc = to_clk_spc(hw); + + return ve_spc_round_performance(spc->cluster, drate); +} + +static int spc_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_spc *spc = to_clk_spc(hw); + + return ve_spc_set_performance(spc->cluster, rate / 1000); +} + +static struct clk_ops clk_spc_ops = { + .recalc_rate = spc_recalc_rate, + .round_rate = spc_round_rate, + .set_rate = spc_set_rate, +}; + +static struct clk *ve_spc_clk_register(struct device *cpu_dev) +{ + struct clk_init_data init; + struct clk_spc *spc; + + spc = kzalloc(sizeof(*spc), GFP_KERNEL); + if (!spc) { + pr_err("could not allocate spc clk\n"); + return ERR_PTR(-ENOMEM); + } + + spc->hw.init = &init; + spc->cluster = topology_physical_package_id(cpu_dev->id); + + spc->cluster = spc->cluster < 0 ? 0 : spc->cluster; + + init.name = dev_name(cpu_dev); + init.ops = &clk_spc_ops; + init.flags = CLK_IS_ROOT | CLK_GET_RATE_NOCACHE; + init.num_parents = 0; + + return devm_clk_register(cpu_dev, &spc->hw); +} + +static int __init ve_spc_clk_init(void) +{ + int cpu; + struct clk *clk; + + if (!info) + return 0; /* Continue only if SPC is initialised */ + + if (ve_spc_populate_opps(0) || ve_spc_populate_opps(1)) { + pr_err("failed to build OPP table\n"); + return -ENODEV; + } + + for_each_possible_cpu(cpu) { + struct device *cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) { + pr_warn("failed to get cpu%d device\n", cpu); + continue; + } + clk = ve_spc_clk_register(cpu_dev); + if (IS_ERR(clk)) { + pr_warn("failed to register cpu%d clock\n", cpu); + continue; + } + if (clk_register_clkdev(clk, NULL, dev_name(cpu_dev))) { + pr_warn("failed to register cpu%d clock lookup\n", cpu); + continue; + } + + if (ve_init_opp_table(cpu_dev)) + pr_warn("failed to initialise cpu%d opp table\n", cpu); + } + + platform_device_register_simple("vexpress-spc-cpufreq", -1, NULL, 0); + return 0; +} +module_init(ve_spc_clk_init); |