drivers/cpuidle/cpuidle-qcom-spm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
   4  * Copyright (c) 2014,2015, Linaro Ltd.
   5  *
   6  * SAW power controller driver
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/io.h>
  12 #include <linux/slab.h>
  13 #include <linux/of.h>
  14 #include <linux/of_address.h>
  15 #include <linux/of_device.h>
  16 #include <linux/err.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/cpuidle.h>
  19 #include <linux/cpu_pm.h>
  20 #include <linux/qcom_scm.h>
  21
  22 #include <asm/proc-fns.h>
  23 #include <asm/suspend.h>
  24
  25 #include "dt_idle_states.h"
  26
  27 #define MAX_PMIC_DATA           2
  28 #define MAX_SEQ_DATA            64
  29 #define SPM_CTL_INDEX           0x7f
  30 #define SPM_CTL_INDEX_SHIFT     4
  31 #define SPM_CTL_EN              BIT(0)
  32
  33 enum pm_sleep_mode {
  34         PM_SLEEP_MODE_STBY,
  35         PM_SLEEP_MODE_RET,
  36         PM_SLEEP_MODE_SPC,
  37         PM_SLEEP_MODE_PC,
  38         PM_SLEEP_MODE_NR,
  39 };
  40
  41 enum spm_reg {
  42         SPM_REG_CFG,
  43         SPM_REG_SPM_CTL,
  44         SPM_REG_DLY,
  45         SPM_REG_PMIC_DLY,
  46         SPM_REG_PMIC_DATA_0,
  47         SPM_REG_PMIC_DATA_1,
  48         SPM_REG_VCTL,
  49         SPM_REG_SEQ_ENTRY,
  50         SPM_REG_SPM_STS,
  51         SPM_REG_PMIC_STS,
  52         SPM_REG_NR,
  53 };
  54
  55 struct spm_reg_data {
  56         const u8 *reg_offset;
  57         u32 spm_cfg;
  58         u32 spm_dly;
  59         u32 pmic_dly;
  60         u32 pmic_data[MAX_PMIC_DATA];
  61         u8 seq[MAX_SEQ_DATA];
  62         u8 start_index[PM_SLEEP_MODE_NR];
  63 };
  64
  65 struct spm_driver_data {
  66         struct cpuidle_driver cpuidle_driver;
  67         void __iomem *reg_base;
  68         const struct spm_reg_data *reg_data;
  69 };
  70
  71 static const u8 spm_reg_offset_v2_1[SPM_REG_NR] = {
  72         [SPM_REG_CFG]           = 0x08,
  73         [SPM_REG_SPM_CTL]       = 0x30,
  74         [SPM_REG_DLY]           = 0x34,
  75         [SPM_REG_SEQ_ENTRY]     = 0x80,
  76 };
  77
  78 /* SPM register data for 8974, 8084 */
  79 static const struct spm_reg_data spm_reg_8974_8084_cpu  = {
  80         .reg_offset = spm_reg_offset_v2_1,
  81         .spm_cfg = 0x1,
  82         .spm_dly = 0x3C102800,
  83         .seq = { 0x03, 0x0B, 0x0F, 0x00, 0x20, 0x80, 0x10, 0xE8, 0x5B, 0x03,
  84                 0x3B, 0xE8, 0x5B, 0x82, 0x10, 0x0B, 0x30, 0x06, 0x26, 0x30,
  85                 0x0F },
  86         .start_index[PM_SLEEP_MODE_STBY] = 0,
  87         .start_index[PM_SLEEP_MODE_SPC] = 3,
  88 };
  89
  90 static const u8 spm_reg_offset_v1_1[SPM_REG_NR] = {
  91         [SPM_REG_CFG]           = 0x08,
  92         [SPM_REG_SPM_CTL]       = 0x20,
  93         [SPM_REG_PMIC_DLY]      = 0x24,
  94         [SPM_REG_PMIC_DATA_0]   = 0x28,
  95         [SPM_REG_PMIC_DATA_1]   = 0x2C,
  96         [SPM_REG_SEQ_ENTRY]     = 0x80,
  97 };
  98
  99 /* SPM register data for 8064 */
 100 static const struct spm_reg_data spm_reg_8064_cpu = {
 101         .reg_offset = spm_reg_offset_v1_1,
 102         .spm_cfg = 0x1F,
 103         .pmic_dly = 0x02020004,
 104         .pmic_data[0] = 0x0084009C,
 105         .pmic_data[1] = 0x00A4001C,
 106         .seq = { 0x03, 0x0F, 0x00, 0x24, 0x54, 0x10, 0x09, 0x03, 0x01,
 107                 0x10, 0x54, 0x30, 0x0C, 0x24, 0x30, 0x0F },
 108         .start_index[PM_SLEEP_MODE_STBY] = 0,
 109         .start_index[PM_SLEEP_MODE_SPC] = 2,
 110 };
 111
 112 static inline void spm_register_write(struct spm_driver_data *drv,
 113                                         enum spm_reg reg, u32 val)
 114 {
 115         if (drv->reg_data->reg_offset[reg])
 116                 writel_relaxed(val, drv->reg_base +
 117                                 drv->reg_data->reg_offset[reg]);
 118 }
 119
 120 /* Ensure a guaranteed write, before return */
 121 static inline void spm_register_write_sync(struct spm_driver_data *drv,
 122                                         enum spm_reg reg, u32 val)
 123 {
 124         u32 ret;
 125
 126         if (!drv->reg_data->reg_offset[reg])
 127                 return;
 128
 129         do {
 130                 writel_relaxed(val, drv->reg_base +
 131                                 drv->reg_data->reg_offset[reg]);
 132                 ret = readl_relaxed(drv->reg_base +
 133                                 drv->reg_data->reg_offset[reg]);
 134                 if (ret == val)
 135                         break;
 136                 cpu_relax();
 137         } while (1);
 138 }
 139
 140 static inline u32 spm_register_read(struct spm_driver_data *drv,
 141                                         enum spm_reg reg)
 142 {
 143         return readl_relaxed(drv->reg_base + drv->reg_data->reg_offset[reg]);
 144 }
 145
 146 static void spm_set_low_power_mode(struct spm_driver_data *drv,
 147                                         enum pm_sleep_mode mode)
 148 {
 149         u32 start_index;
 150         u32 ctl_val;
 151
 152         start_index = drv->reg_data->start_index[mode];
 153
 154         ctl_val = spm_register_read(drv, SPM_REG_SPM_CTL);
 155         ctl_val &= ~(SPM_CTL_INDEX << SPM_CTL_INDEX_SHIFT);
 156         ctl_val |= start_index << SPM_CTL_INDEX_SHIFT;
 157         ctl_val |= SPM_CTL_EN;
 158         spm_register_write_sync(drv, SPM_REG_SPM_CTL, ctl_val);
 159 }
 160
 161 static int qcom_pm_collapse(unsigned long int unused)
 162 {
 163         qcom_scm_cpu_power_down(QCOM_SCM_CPU_PWR_DOWN_L2_ON);
 164
 165         /*
 166          * Returns here only if there was a pending interrupt and we did not
 167          * power down as a result.
 168          */
 169         return -1;
 170 }
 171
 172 static int qcom_cpu_spc(struct spm_driver_data *drv)
 173 {
 174         int ret;
 175
 176         spm_set_low_power_mode(drv, PM_SLEEP_MODE_SPC);
 177         ret = cpu_suspend(0, qcom_pm_collapse);
 178         /*
 179          * ARM common code executes WFI without calling into our driver and
 180          * if the SPM mode is not reset, then we may accidently power down the
 181          * cpu when we intended only to gate the cpu clock.
 182          * Ensure the state is set to standby before returning.
 183          */
 184         spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
 185
 186         return ret;
 187 }
 188
 189 static int spm_enter_idle_state(struct cpuidle_device *dev,
 190                                 struct cpuidle_driver *drv, int idx)
 191 {
 192         struct spm_driver_data *data = container_of(drv, struct spm_driver_data,
 193                                                     cpuidle_driver);
 194
 195         return CPU_PM_CPU_IDLE_ENTER_PARAM(qcom_cpu_spc, idx, data);
 196 }
 197
 198 static struct cpuidle_driver qcom_spm_idle_driver = {
 199         .name = "qcom_spm",
 200         .owner = THIS_MODULE,
 201         .states[0] = {
 202                 .enter                  = spm_enter_idle_state,
 203                 .exit_latency           = 1,
 204                 .target_residency       = 1,
 205                 .power_usage            = UINT_MAX,
 206                 .name                   = "WFI",
 207                 .desc                   = "ARM WFI",
 208         }
 209 };
 210
 211 static const struct of_device_id qcom_idle_state_match[] = {
 212         { .compatible = "qcom,idle-state-spc", .data = spm_enter_idle_state },
 213         { },
 214 };
 215
 216 static int spm_cpuidle_init(struct cpuidle_driver *drv, int cpu)
 217 {
 218         int ret;
 219
 220         memcpy(drv, &qcom_spm_idle_driver, sizeof(*drv));
 221         drv->cpumask = (struct cpumask *)cpumask_of(cpu);
 222
 223         /* Parse idle states from device tree */
 224         ret = dt_init_idle_driver(drv, qcom_idle_state_match, 1);
 225         if (ret <= 0)
 226                 return ret ? : -ENODEV;
 227
 228         /* We have atleast one power down mode */
 229         return qcom_scm_set_warm_boot_addr(cpu_resume_arm, drv->cpumask);
 230 }
 231
 232 static struct spm_driver_data *spm_get_drv(struct platform_device *pdev,
 233                 int *spm_cpu)
 234 {
 235         struct spm_driver_data *drv = NULL;
 236         struct device_node *cpu_node, *saw_node;
 237         int cpu;
 238         bool found = 0;
 239
 240         for_each_possible_cpu(cpu) {
 241                 cpu_node = of_cpu_device_node_get(cpu);
 242                 if (!cpu_node)
 243                         continue;
 244                 saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
 245                 found = (saw_node == pdev->dev.of_node);
 246                 of_node_put(saw_node);
 247                 of_node_put(cpu_node);
 248                 if (found)
 249                         break;
 250         }
 251
 252         if (found) {
 253                 drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
 254                 if (drv)
 255                         *spm_cpu = cpu;
 256         }
 257
 258         return drv;
 259 }
 260
 261 static const struct of_device_id spm_match_table[] = {
 262         { .compatible = "qcom,msm8974-saw2-v2.1-cpu",
 263           .data = &spm_reg_8974_8084_cpu },
 264         { .compatible = "qcom,apq8084-saw2-v2.1-cpu",
 265           .data = &spm_reg_8974_8084_cpu },
 266         { .compatible = "qcom,apq8064-saw2-v1.1-cpu",
 267           .data = &spm_reg_8064_cpu },
 268         { },
 269 };
 270
 271 static int spm_dev_probe(struct platform_device *pdev)
 272 {
 273         struct spm_driver_data *drv;
 274         struct resource *res;
 275         const struct of_device_id *match_id;
 276         void __iomem *addr;
 277         int cpu, ret;
 278
 279         if (!qcom_scm_is_available())
 280                 return -EPROBE_DEFER;
 281
 282         drv = spm_get_drv(pdev, &cpu);
 283         if (!drv)
 284                 return -EINVAL;
 285         platform_set_drvdata(pdev, drv);
 286
 287         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 288         drv->reg_base = devm_ioremap_resource(&pdev->dev, res);
 289         if (IS_ERR(drv->reg_base))
 290                 return PTR_ERR(drv->reg_base);
 291
 292         match_id = of_match_node(spm_match_table, pdev->dev.of_node);
 293         if (!match_id)
 294                 return -ENODEV;
 295
 296         drv->reg_data = match_id->data;
 297
 298         ret = spm_cpuidle_init(&drv->cpuidle_driver, cpu);
 299         if (ret)
 300                 return ret;
 301
 302         /* Write the SPM sequences first.. */
 303         addr = drv->reg_base + drv->reg_data->reg_offset[SPM_REG_SEQ_ENTRY];
 304         __iowrite32_copy(addr, drv->reg_data->seq,
 305                         ARRAY_SIZE(drv->reg_data->seq) / 4);
 306
 307         /*
 308          * ..and then the control registers.
 309          * On some SoC if the control registers are written first and if the
 310          * CPU was held in reset, the reset signal could trigger the SPM state
 311          * machine, before the sequences are completely written.
 312          */
 313         spm_register_write(drv, SPM_REG_CFG, drv->reg_data->spm_cfg);
 314         spm_register_write(drv, SPM_REG_DLY, drv->reg_data->spm_dly);
 315         spm_register_write(drv, SPM_REG_PMIC_DLY, drv->reg_data->pmic_dly);
 316         spm_register_write(drv, SPM_REG_PMIC_DATA_0,
 317                                 drv->reg_data->pmic_data[0]);
 318         spm_register_write(drv, SPM_REG_PMIC_DATA_1,
 319                                 drv->reg_data->pmic_data[1]);
 320
 321         /* Set up Standby as the default low power mode */
 322         spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
 323
 324         return cpuidle_register(&drv->cpuidle_driver, NULL);
 325 }
 326
 327 static int spm_dev_remove(struct platform_device *pdev)
 328 {
 329         struct spm_driver_data *drv = platform_get_drvdata(pdev);
 330
 331         cpuidle_unregister(&drv->cpuidle_driver);
 332         return 0;
 333 }
 334
 335 static struct platform_driver spm_driver = {
 336         .probe = spm_dev_probe,
 337         .remove = spm_dev_remove,
 338         .driver = {
 339                 .name = "saw",
 340                 .of_match_table = spm_match_table,
 341         },
 342 };
 343
 344 builtin_platform_driver(spm_driver);