1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * R-Car Gen4 SYSC Power management support 4 * 5 * Copyright (C) 2021 Renesas Electronics Corp. 6 */ 7 8 #include <linux/bits.h> 9 #include <linux/clk/renesas.h> 10 #include <linux/delay.h> 11 #include <linux/err.h> 12 #include <linux/io.h> 13 #include <linux/iopoll.h> 14 #include <linux/kernel.h> 15 #include <linux/mm.h> 16 #include <linux/of_address.h> 17 #include <linux/pm_domain.h> 18 #include <linux/slab.h> 19 #include <linux/spinlock.h> 20 #include <linux/types.h> 21 22 #include "rcar-gen4-sysc.h" 23 24 /* SYSC Common */ 25 #define SYSCSR 0x000 /* SYSC Status Register */ 26 #define SYSCPONSR(x) (0x800 + ((x) * 0x4)) /* Power-ON Status Register 0 */ 27 #define SYSCPOFFSR(x) (0x808 + ((x) * 0x4)) /* Power-OFF Status Register */ 28 #define SYSCISCR(x) (0x810 + ((x) * 0x4)) /* Interrupt Status/Clear Register */ 29 #define SYSCIER(x) (0x820 + ((x) * 0x4)) /* Interrupt Enable Register */ 30 #define SYSCIMR(x) (0x830 + ((x) * 0x4)) /* Interrupt Mask Register */ 31 32 /* Power Domain Registers */ 33 #define PDRSR(n) (0x1000 + ((n) * 0x40)) 34 #define PDRONCR(n) (0x1004 + ((n) * 0x40)) 35 #define PDROFFCR(n) (0x1008 + ((n) * 0x40)) 36 #define PDRESR(n) (0x100C + ((n) * 0x40)) 37 38 /* PWRON/PWROFF */ 39 #define PWRON_PWROFF BIT(0) /* Power-ON/OFF request */ 40 41 /* PDRESR */ 42 #define PDRESR_ERR BIT(0) 43 44 /* PDRSR */ 45 #define PDRSR_OFF BIT(0) /* Power-OFF state */ 46 #define PDRSR_ON BIT(4) /* Power-ON state */ 47 #define PDRSR_OFF_STATE BIT(8) /* Processing Power-OFF sequence */ 48 #define PDRSR_ON_STATE BIT(12) /* Processing Power-ON sequence */ 49 50 #define SYSCSR_BUSY GENMASK(1, 0) /* All bit sets is not busy */ 51 52 #define SYSCSR_TIMEOUT 10000 53 #define SYSCSR_DELAY_US 10 54 55 #define PDRESR_RETRIES 1000 56 #define PDRESR_DELAY_US 10 57 58 #define SYSCISR_TIMEOUT 10000 59 #define SYSCISR_DELAY_US 10 60 61 #define RCAR_GEN4_PD_ALWAYS_ON 64 62 #define NUM_DOMAINS_EACH_REG BITS_PER_TYPE(u32) 63 64 static void __iomem *rcar_gen4_sysc_base; 65 static DEFINE_SPINLOCK(rcar_gen4_sysc_lock); /* SMP CPUs + I/O devices */ 66 67 static int rcar_gen4_sysc_pwr_on_off(u8 pdr, bool on) 68 { 69 unsigned int reg_offs; 70 u32 val; 71 int ret; 72 73 if (on) 74 reg_offs = PDRONCR(pdr); 75 else 76 reg_offs = PDROFFCR(pdr); 77 78 /* Wait until SYSC is ready to accept a power request */ 79 ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCSR, val, 80 (val & SYSCSR_BUSY) == SYSCSR_BUSY, 81 SYSCSR_DELAY_US, SYSCSR_TIMEOUT); 82 if (ret < 0) 83 return -EAGAIN; 84 85 /* Submit power shutoff or power resume request */ 86 iowrite32(PWRON_PWROFF, rcar_gen4_sysc_base + reg_offs); 87 88 return 0; 89 } 90 91 static int clear_irq_flags(unsigned int reg_idx, unsigned int isr_mask) 92 { 93 u32 val; 94 int ret; 95 96 iowrite32(isr_mask, rcar_gen4_sysc_base + SYSCISCR(reg_idx)); 97 98 ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx), 99 val, !(val & isr_mask), 100 SYSCISR_DELAY_US, SYSCISR_TIMEOUT); 101 if (ret < 0) { 102 pr_err("\n %s : Can not clear IRQ flags in SYSCISCR", __func__); 103 return -EIO; 104 } 105 106 return 0; 107 } 108 109 static int rcar_gen4_sysc_power(u8 pdr, bool on) 110 { 111 unsigned int isr_mask; 112 unsigned int reg_idx, bit_idx; 113 unsigned int status; 114 unsigned long flags; 115 int ret = 0; 116 u32 val; 117 int k; 118 119 spin_lock_irqsave(&rcar_gen4_sysc_lock, flags); 120 121 reg_idx = pdr / NUM_DOMAINS_EACH_REG; 122 bit_idx = pdr % NUM_DOMAINS_EACH_REG; 123 124 isr_mask = BIT(bit_idx); 125 126 /* 127 * The interrupt source needs to be enabled, but masked, to prevent the 128 * CPU from receiving it. 129 */ 130 iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIER(reg_idx)) | isr_mask, 131 rcar_gen4_sysc_base + SYSCIER(reg_idx)); 132 iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIMR(reg_idx)) | isr_mask, 133 rcar_gen4_sysc_base + SYSCIMR(reg_idx)); 134 135 ret = clear_irq_flags(reg_idx, isr_mask); 136 if (ret) 137 goto out; 138 139 /* Submit power shutoff or resume request until it was accepted */ 140 for (k = 0; k < PDRESR_RETRIES; k++) { 141 ret = rcar_gen4_sysc_pwr_on_off(pdr, on); 142 if (ret) 143 goto out; 144 145 status = ioread32(rcar_gen4_sysc_base + PDRESR(pdr)); 146 if (!(status & PDRESR_ERR)) 147 break; 148 149 udelay(PDRESR_DELAY_US); 150 } 151 152 if (k == PDRESR_RETRIES) { 153 ret = -EIO; 154 goto out; 155 } 156 157 /* Wait until the power shutoff or resume request has completed * */ 158 ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx), 159 val, (val & isr_mask), 160 SYSCISR_DELAY_US, SYSCISR_TIMEOUT); 161 if (ret < 0) { 162 ret = -EIO; 163 goto out; 164 } 165 166 /* Clear interrupt flags */ 167 ret = clear_irq_flags(reg_idx, isr_mask); 168 if (ret) 169 goto out; 170 171 out: 172 spin_unlock_irqrestore(&rcar_gen4_sysc_lock, flags); 173 174 pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off", 175 pdr, ioread32(rcar_gen4_sysc_base + SYSCISCR(reg_idx)), ret); 176 return ret; 177 } 178 179 static bool rcar_gen4_sysc_power_is_off(u8 pdr) 180 { 181 unsigned int st; 182 183 st = ioread32(rcar_gen4_sysc_base + PDRSR(pdr)); 184 185 if (st & PDRSR_OFF) 186 return true; 187 188 return false; 189 } 190 191 struct rcar_gen4_sysc_pd { 192 struct generic_pm_domain genpd; 193 u8 pdr; 194 unsigned int flags; 195 char name[]; 196 }; 197 198 static inline struct rcar_gen4_sysc_pd *to_rcar_gen4_pd(struct generic_pm_domain *d) 199 { 200 return container_of(d, struct rcar_gen4_sysc_pd, genpd); 201 } 202 203 static int rcar_gen4_sysc_pd_power_off(struct generic_pm_domain *genpd) 204 { 205 struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd); 206 207 pr_debug("%s: %s\n", __func__, genpd->name); 208 return rcar_gen4_sysc_power(pd->pdr, false); 209 } 210 211 static int rcar_gen4_sysc_pd_power_on(struct generic_pm_domain *genpd) 212 { 213 struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd); 214 215 pr_debug("%s: %s\n", __func__, genpd->name); 216 return rcar_gen4_sysc_power(pd->pdr, true); 217 } 218 219 static int __init rcar_gen4_sysc_pd_setup(struct rcar_gen4_sysc_pd *pd) 220 { 221 struct generic_pm_domain *genpd = &pd->genpd; 222 const char *name = pd->genpd.name; 223 int error; 224 225 if (pd->flags & PD_CPU) { 226 /* 227 * This domain contains a CPU core and therefore it should 228 * only be turned off if the CPU is not in use. 229 */ 230 pr_debug("PM domain %s contains %s\n", name, "CPU"); 231 genpd->flags |= GENPD_FLAG_ALWAYS_ON; 232 } else if (pd->flags & PD_SCU) { 233 /* 234 * This domain contains an SCU and cache-controller, and 235 * therefore it should only be turned off if the CPU cores are 236 * not in use. 237 */ 238 pr_debug("PM domain %s contains %s\n", name, "SCU"); 239 genpd->flags |= GENPD_FLAG_ALWAYS_ON; 240 } else if (pd->flags & PD_NO_CR) { 241 /* 242 * This domain cannot be turned off. 243 */ 244 genpd->flags |= GENPD_FLAG_ALWAYS_ON; 245 } 246 247 if (!(pd->flags & (PD_CPU | PD_SCU))) { 248 /* Enable Clock Domain for I/O devices */ 249 genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP; 250 genpd->attach_dev = cpg_mssr_attach_dev; 251 genpd->detach_dev = cpg_mssr_detach_dev; 252 } 253 254 genpd->power_off = rcar_gen4_sysc_pd_power_off; 255 genpd->power_on = rcar_gen4_sysc_pd_power_on; 256 257 if (pd->flags & (PD_CPU | PD_NO_CR)) { 258 /* Skip CPUs (handled by SMP code) and areas without control */ 259 pr_debug("%s: Not touching %s\n", __func__, genpd->name); 260 goto finalize; 261 } 262 263 if (!rcar_gen4_sysc_power_is_off(pd->pdr)) { 264 pr_debug("%s: %s is already powered\n", __func__, genpd->name); 265 goto finalize; 266 } 267 268 rcar_gen4_sysc_power(pd->pdr, true); 269 270 finalize: 271 error = pm_genpd_init(genpd, &simple_qos_governor, false); 272 if (error) 273 pr_err("Failed to init PM domain %s: %d\n", name, error); 274 275 return error; 276 } 277 278 static const struct of_device_id rcar_gen4_sysc_matches[] __initconst = { 279 #ifdef CONFIG_SYSC_R8A779A0 280 { .compatible = "renesas,r8a779a0-sysc", .data = &r8a779a0_sysc_info }, 281 #endif 282 #ifdef CONFIG_SYSC_R8A779F0 283 { .compatible = "renesas,r8a779f0-sysc", .data = &r8a779f0_sysc_info }, 284 #endif 285 #ifdef CONFIG_SYSC_R8A779G0 286 { .compatible = "renesas,r8a779g0-sysc", .data = &r8a779g0_sysc_info }, 287 #endif 288 { /* sentinel */ } 289 }; 290 291 struct rcar_gen4_pm_domains { 292 struct genpd_onecell_data onecell_data; 293 struct generic_pm_domain *domains[RCAR_GEN4_PD_ALWAYS_ON + 1]; 294 }; 295 296 static struct genpd_onecell_data *rcar_gen4_sysc_onecell_data; 297 298 static int __init rcar_gen4_sysc_pd_init(void) 299 { 300 const struct rcar_gen4_sysc_info *info; 301 const struct of_device_id *match; 302 struct rcar_gen4_pm_domains *domains; 303 struct device_node *np; 304 void __iomem *base; 305 unsigned int i; 306 int error; 307 308 np = of_find_matching_node_and_match(NULL, rcar_gen4_sysc_matches, &match); 309 if (!np) 310 return -ENODEV; 311 312 info = match->data; 313 314 base = of_iomap(np, 0); 315 if (!base) { 316 pr_warn("%pOF: Cannot map regs\n", np); 317 error = -ENOMEM; 318 goto out_put; 319 } 320 321 rcar_gen4_sysc_base = base; 322 323 domains = kzalloc(sizeof(*domains), GFP_KERNEL); 324 if (!domains) { 325 error = -ENOMEM; 326 goto out_put; 327 } 328 329 domains->onecell_data.domains = domains->domains; 330 domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains); 331 rcar_gen4_sysc_onecell_data = &domains->onecell_data; 332 333 for (i = 0; i < info->num_areas; i++) { 334 const struct rcar_gen4_sysc_area *area = &info->areas[i]; 335 struct rcar_gen4_sysc_pd *pd; 336 size_t n; 337 338 if (!area->name) { 339 /* Skip NULLified area */ 340 continue; 341 } 342 343 n = strlen(area->name) + 1; 344 pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL); 345 if (!pd) { 346 error = -ENOMEM; 347 goto out_put; 348 } 349 350 memcpy(pd->name, area->name, n); 351 pd->genpd.name = pd->name; 352 pd->pdr = area->pdr; 353 pd->flags = area->flags; 354 355 error = rcar_gen4_sysc_pd_setup(pd); 356 if (error) 357 goto out_put; 358 359 domains->domains[area->pdr] = &pd->genpd; 360 361 if (area->parent < 0) 362 continue; 363 364 error = pm_genpd_add_subdomain(domains->domains[area->parent], 365 &pd->genpd); 366 if (error) { 367 pr_warn("Failed to add PM subdomain %s to parent %u\n", 368 area->name, area->parent); 369 goto out_put; 370 } 371 } 372 373 error = of_genpd_add_provider_onecell(np, &domains->onecell_data); 374 375 out_put: 376 of_node_put(np); 377 return error; 378 } 379 early_initcall(rcar_gen4_sysc_pd_init); 380