diff options
Diffstat (limited to 'arch/arm/mach-vexpress/spc.c')
-rw-r--r-- | arch/arm/mach-vexpress/spc.c | 366 |
1 files changed, 365 insertions, 1 deletions
diff --git a/arch/arm/mach-vexpress/spc.c b/arch/arm/mach-vexpress/spc.c index eefb029..033d34d 100644 --- a/arch/arm/mach-vexpress/spc.c +++ b/arch/arm/mach-vexpress/spc.c @@ -17,14 +17,31 @@ * 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 @@ -36,12 +53,45 @@ #define A15_BX_ADDR0 0x68 #define A7_BX_ADDR0 0x78 +/* 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; /* @@ -49,6 +99,12 @@ struct ve_spc_drvdata { * 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; @@ -157,8 +213,197 @@ void ve_spc_powerdown(u32 cluster, bool enable) writel_relaxed(enable, info->baseaddr + pwdrn_reg); } -int __init ve_spc_init(void __iomem *baseaddr, u32 a15_clusid) +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 | + * +--------------------------+ + * | u_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; + } else { + break; + } + } + info->num_opps[cluster] = idx; + + return ret; +} + +static int ve_init_opp_table(struct device *cpu_dev) +{ + int cluster = topology_physical_package_id(cpu_dev->id); + int idx, ret = 0, max_opp = info->num_opps[cluster]; + struct ve_spc_opp *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"); @@ -168,6 +413,25 @@ int __init ve_spc_init(void __iomem *baseaddr, u32 a15_clusid) 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 @@ -178,3 +442,103 @@ int __init ve_spc_init(void __iomem *baseaddr, u32 a15_clusid) 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); + + 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); |