drivers/soc/qcom/spm.c

   1 /*
   2  * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
   3  * Copyright (c) 2014,2015, Linaro Ltd.
   4  *
   5  * SAW power controller driver
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 and
   9  * only version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/io.h>
  20 #include <linux/slab.h>
  21 #include <linux/of.h>
  22 #include <linux/of_address.h>
  23 #include <linux/of_device.h>
  24 #include <linux/err.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/cpuidle.h>
  27 #include <linux/cpu_pm.h>
  28 #include <linux/qcom_scm.h>
  29
  30 #include <asm/cpuidle.h>
  31 #include <asm/proc-fns.h>
  32 #include <asm/suspend.h>
  33
  34 #define MAX_PMIC_DATA           2
  35 #define MAX_SEQ_DATA            64
  36 #define SPM_CTL_INDEX           0x7f
  37 #define SPM_CTL_INDEX_SHIFT     4
  38 #define SPM_CTL_EN              BIT(0)
  39
  40 enum pm_sleep_mode {
  41         PM_SLEEP_MODE_STBY,
  42         PM_SLEEP_MODE_RET,
  43         PM_SLEEP_MODE_SPC,
  44         PM_SLEEP_MODE_PC,
  45         PM_SLEEP_MODE_NR,
  46 };
  47
  48 enum spm_reg {
  49         SPM_REG_CFG,
  50         SPM_REG_SPM_CTL,
  51         SPM_REG_DLY,
  52         SPM_REG_PMIC_DLY,
  53         SPM_REG_PMIC_DATA_0,
  54         SPM_REG_PMIC_DATA_1,
  55         SPM_REG_VCTL,
  56         SPM_REG_SEQ_ENTRY,
  57         SPM_REG_SPM_STS,
  58         SPM_REG_PMIC_STS,
  59         SPM_REG_NR,
  60 };
  61
  62 struct spm_reg_data {
  63         const u8 *reg_offset;
  64         u32 spm_cfg;
  65         u32 spm_dly;
  66         u32 pmic_dly;
  67         u32 pmic_data[MAX_PMIC_DATA];
  68         u8 seq[MAX_SEQ_DATA];
  69         u8 start_index[PM_SLEEP_MODE_NR];
  70 };
  71
  72 struct spm_driver_data {
  73         void __iomem *reg_base;
  74         const struct spm_reg_data *reg_data;
  75 };
  76
  77 static const u8 spm_reg_offset_v2_1[SPM_REG_NR] = {
  78         [SPM_REG_CFG]           = 0x08,
  79         [SPM_REG_SPM_CTL]       = 0x30,
  80         [SPM_REG_DLY]           = 0x34,
  81         [SPM_REG_SEQ_ENTRY]     = 0x80,
  82 };
  83
  84 /* SPM register data for 8974, 8084 */
  85 static const struct spm_reg_data spm_reg_8974_8084_cpu  = {
  86         .reg_offset = spm_reg_offset_v2_1,
  87         .spm_cfg = 0x1,
  88         .spm_dly = 0x3C102800,
  89         .seq = { 0x03, 0x0B, 0x0F, 0x00, 0x20, 0x80, 0x10, 0xE8, 0x5B, 0x03,
  90                 0x3B, 0xE8, 0x5B, 0x82, 0x10, 0x0B, 0x30, 0x06, 0x26, 0x30,
  91                 0x0F },
  92         .start_index[PM_SLEEP_MODE_STBY] = 0,
  93         .start_index[PM_SLEEP_MODE_SPC] = 3,
  94 };
  95
  96 static const u8 spm_reg_offset_v1_1[SPM_REG_NR] = {
  97         [SPM_REG_CFG]           = 0x08,
  98         [SPM_REG_SPM_CTL]       = 0x20,
  99         [SPM_REG_PMIC_DLY]      = 0x24,
 100         [SPM_REG_PMIC_DATA_0]   = 0x28,
 101         [SPM_REG_PMIC_DATA_1]   = 0x2C,
 102         [SPM_REG_SEQ_ENTRY]     = 0x80,
 103 };
 104
 105 /* SPM register data for 8064 */
 106 static const struct spm_reg_data spm_reg_8064_cpu = {
 107         .reg_offset = spm_reg_offset_v1_1,
 108         .spm_cfg = 0x1F,
 109         .pmic_dly = 0x02020004,
 110         .pmic_data[0] = 0x0084009C,
 111         .pmic_data[1] = 0x00A4001C,
 112         .seq = { 0x03, 0x0F, 0x00, 0x24, 0x54, 0x10, 0x09, 0x03, 0x01,
 113                 0x10, 0x54, 0x30, 0x0C, 0x24, 0x30, 0x0F },
 114         .start_index[PM_SLEEP_MODE_STBY] = 0,
 115         .start_index[PM_SLEEP_MODE_SPC] = 2,
 116 };
 117
 118 static DEFINE_PER_CPU(struct spm_driver_data *, cpu_spm_drv);
 119
 120 typedef int (*idle_fn)(void);
 121 static DEFINE_PER_CPU(idle_fn*, qcom_idle_ops);
 122
 123 static inline void spm_register_write(struct spm_driver_data *drv,
 124                                         enum spm_reg reg, u32 val)
 125 {
 126         if (drv->reg_data->reg_offset[reg])
 127                 writel_relaxed(val, drv->reg_base +
 128                                 drv->reg_data->reg_offset[reg]);
 129 }
 130
 131 /* Ensure a guaranteed write, before return */
 132 static inline void spm_register_write_sync(struct spm_driver_data *drv,
 133                                         enum spm_reg reg, u32 val)
 134 {
 135         u32 ret;
 136
 137         if (!drv->reg_data->reg_offset[reg])
 138                 return;
 139
 140         do {
 141                 writel_relaxed(val, drv->reg_base +
 142                                 drv->reg_data->reg_offset[reg]);
 143                 ret = readl_relaxed(drv->reg_base +
 144                                 drv->reg_data->reg_offset[reg]);
 145                 if (ret == val)
 146                         break;
 147                 cpu_relax();
 148         } while (1);
 149 }
 150
 151 static inline u32 spm_register_read(struct spm_driver_data *drv,
 152                                         enum spm_reg reg)
 153 {
 154         return readl_relaxed(drv->reg_base + drv->reg_data->reg_offset[reg]);
 155 }
 156
 157 static void spm_set_low_power_mode(struct spm_driver_data *drv,
 158                                         enum pm_sleep_mode mode)
 159 {
 160         u32 start_index;
 161         u32 ctl_val;
 162
 163         start_index = drv->reg_data->start_index[mode];
 164
 165         ctl_val = spm_register_read(drv, SPM_REG_SPM_CTL);
 166         ctl_val &= ~(SPM_CTL_INDEX << SPM_CTL_INDEX_SHIFT);
 167         ctl_val |= start_index << SPM_CTL_INDEX_SHIFT;
 168         ctl_val |= SPM_CTL_EN;
 169         spm_register_write_sync(drv, SPM_REG_SPM_CTL, ctl_val);
 170 }
 171
 172 static int qcom_pm_collapse(unsigned long int unused)
 173 {
 174         qcom_scm_cpu_power_down(QCOM_SCM_CPU_PWR_DOWN_L2_ON);
 175
 176         /*
 177          * Returns here only if there was a pending interrupt and we did not
 178          * power down as a result.
 179          */
 180         return -1;
 181 }
 182
 183 static int qcom_cpu_spc(void)
 184 {
 185         int ret;
 186         struct spm_driver_data *drv = __this_cpu_read(cpu_spm_drv);
 187
 188         spm_set_low_power_mode(drv, PM_SLEEP_MODE_SPC);
 189         ret = cpu_suspend(0, qcom_pm_collapse);
 190         /*
 191          * ARM common code executes WFI without calling into our driver and
 192          * if the SPM mode is not reset, then we may accidently power down the
 193          * cpu when we intended only to gate the cpu clock.
 194          * Ensure the state is set to standby before returning.
 195          */
 196         spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
 197
 198         return ret;
 199 }
 200
 201 static int qcom_idle_enter(unsigned long index)
 202 {
 203         return __this_cpu_read(qcom_idle_ops)[index]();
 204 }
 205
 206 static const struct of_device_id qcom_idle_state_match[] __initconst = {
 207         { .compatible = "qcom,idle-state-spc", .data = qcom_cpu_spc },
 208         { },
 209 };
 210
 211 static int __init qcom_cpuidle_init(struct device_node *cpu_node, int cpu)
 212 {
 213         const struct of_device_id *match_id;
 214         struct device_node *state_node;
 215         int i;
 216         int state_count = 1;
 217         idle_fn idle_fns[CPUIDLE_STATE_MAX];
 218         idle_fn *fns;
 219         cpumask_t mask;
 220         bool use_scm_power_down = false;
 221
 222         for (i = 0; ; i++) {
 223                 state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
 224                 if (!state_node)
 225                         break;
 226
 227                 if (!of_device_is_available(state_node))
 228                         continue;
 229
 230                 if (i == CPUIDLE_STATE_MAX) {
 231                         pr_warn("%s: cpuidle states reached max possible\n",
 232                                         __func__);
 233                         break;
 234                 }
 235
 236                 match_id = of_match_node(qcom_idle_state_match, state_node);
 237                 if (!match_id)
 238                         return -ENODEV;
 239
 240                 idle_fns[state_count] = match_id->data;
 241
 242                 /* Check if any of the states allow power down */
 243                 if (match_id->data == qcom_cpu_spc)
 244                         use_scm_power_down = true;
 245
 246                 state_count++;
 247         }
 248
 249         if (state_count == 1)
 250                 goto check_spm;
 251
 252         fns = devm_kcalloc(get_cpu_device(cpu), state_count, sizeof(*fns),
 253                         GFP_KERNEL);
 254         if (!fns)
 255                 return -ENOMEM;
 256
 257         for (i = 1; i < state_count; i++)
 258                 fns[i] = idle_fns[i];
 259
 260         if (use_scm_power_down) {
 261                 /* We have atleast one power down mode */
 262                 cpumask_clear(&mask);
 263                 cpumask_set_cpu(cpu, &mask);
 264                 qcom_scm_set_warm_boot_addr(cpu_resume_arm, &mask);
 265         }
 266
 267         per_cpu(qcom_idle_ops, cpu) = fns;
 268
 269         /*
 270          * SPM probe for the cpu should have happened by now, if the
 271          * SPM device does not exist, return -ENXIO to indicate that the
 272          * cpu does not support idle states.
 273          */
 274 check_spm:
 275         return per_cpu(cpu_spm_drv, cpu) ? 0 : -ENXIO;
 276 }
 277
 278 static const struct cpuidle_ops qcom_cpuidle_ops __initconst = {
 279         .suspend = qcom_idle_enter,
 280         .init = qcom_cpuidle_init,
 281 };
 282
 283 CPUIDLE_METHOD_OF_DECLARE(qcom_idle_v1, "qcom,kpss-acc-v1", &qcom_cpuidle_ops);
 284 CPUIDLE_METHOD_OF_DECLARE(qcom_idle_v2, "qcom,kpss-acc-v2", &qcom_cpuidle_ops);
 285
 286 static struct spm_driver_data *spm_get_drv(struct platform_device *pdev,
 287                 int *spm_cpu)
 288 {
 289         struct spm_driver_data *drv = NULL;
 290         struct device_node *cpu_node, *saw_node;
 291         int cpu;
 292         bool found = 0;
 293
 294         for_each_possible_cpu(cpu) {
 295                 cpu_node = of_cpu_device_node_get(cpu);
 296                 if (!cpu_node)
 297                         continue;
 298                 saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
 299                 found = (saw_node == pdev->dev.of_node);
 300                 of_node_put(saw_node);
 301                 of_node_put(cpu_node);
 302                 if (found)
 303                         break;
 304         }
 305
 306         if (found) {
 307                 drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
 308                 if (drv)
 309                         *spm_cpu = cpu;
 310         }
 311
 312         return drv;
 313 }
 314
 315 static const struct of_device_id spm_match_table[] = {
 316         { .compatible = "qcom,msm8974-saw2-v2.1-cpu",
 317           .data = &spm_reg_8974_8084_cpu },
 318         { .compatible = "qcom,apq8084-saw2-v2.1-cpu",
 319           .data = &spm_reg_8974_8084_cpu },
 320         { .compatible = "qcom,apq8064-saw2-v1.1-cpu",
 321           .data = &spm_reg_8064_cpu },
 322         { },
 323 };
 324
 325 static int spm_dev_probe(struct platform_device *pdev)
 326 {
 327         struct spm_driver_data *drv;
 328         struct resource *res;
 329         const struct of_device_id *match_id;
 330         void __iomem *addr;
 331         int cpu;
 332
 333         drv = spm_get_drv(pdev, &cpu);
 334         if (!drv)
 335                 return -EINVAL;
 336
 337         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 338         drv->reg_base = devm_ioremap_resource(&pdev->dev, res);
 339         if (IS_ERR(drv->reg_base))
 340                 return PTR_ERR(drv->reg_base);
 341
 342         match_id = of_match_node(spm_match_table, pdev->dev.of_node);
 343         if (!match_id)
 344                 return -ENODEV;
 345
 346         drv->reg_data = match_id->data;
 347
 348         /* Write the SPM sequences first.. */
 349         addr = drv->reg_base + drv->reg_data->reg_offset[SPM_REG_SEQ_ENTRY];
 350         __iowrite32_copy(addr, drv->reg_data->seq,
 351                         ARRAY_SIZE(drv->reg_data->seq) / 4);
 352
 353         /*
 354          * ..and then the control registers.
 355          * On some SoC if the control registers are written first and if the
 356          * CPU was held in reset, the reset signal could trigger the SPM state
 357          * machine, before the sequences are completely written.
 358          */
 359         spm_register_write(drv, SPM_REG_CFG, drv->reg_data->spm_cfg);
 360         spm_register_write(drv, SPM_REG_DLY, drv->reg_data->spm_dly);
 361         spm_register_write(drv, SPM_REG_PMIC_DLY, drv->reg_data->pmic_dly);
 362         spm_register_write(drv, SPM_REG_PMIC_DATA_0,
 363                                 drv->reg_data->pmic_data[0]);
 364         spm_register_write(drv, SPM_REG_PMIC_DATA_1,
 365                                 drv->reg_data->pmic_data[1]);
 366
 367         /* Set up Standby as the default low power mode */
 368         spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
 369
 370         per_cpu(cpu_spm_drv, cpu) = drv;
 371
 372         return 0;
 373 }
 374
 375 static struct platform_driver spm_driver = {
 376         .probe = spm_dev_probe,
 377         .driver = {
 378                 .name = "saw",
 379                 .of_match_table = spm_match_table,
 380         },
 381 };
 382
 383 builtin_platform_driver(spm_driver);