Andy Shevchenko | 5823d08 | 2016-06-14 21:29:45 +0300 | [diff] [blame] | 1 | /* |
| 2 | * Intel MID Power Management Unit (PWRMU) device driver |
| 3 | * |
| 4 | * Copyright (C) 2016, Intel Corporation |
| 5 | * |
| 6 | * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify it |
| 9 | * under the terms and conditions of the GNU General Public License, |
| 10 | * version 2, as published by the Free Software Foundation. |
| 11 | * |
| 12 | * Intel MID Power Management Unit device driver handles the South Complex PCI |
| 13 | * devices such as GPDMA, SPI, I2C, PWM, and so on. By default PCI core |
| 14 | * modifies bits in PMCSR register in the PCI configuration space. This is not |
| 15 | * enough on some SoCs like Intel Tangier. In such case PCI core sets a new |
| 16 | * power state of the device in question through a PM hook registered in struct |
| 17 | * pci_platform_pm_ops (see drivers/pci/pci-mid.c). |
| 18 | */ |
| 19 | |
| 20 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 21 | |
| 22 | #include <linux/delay.h> |
| 23 | #include <linux/errno.h> |
Andy Shevchenko | 5823d08 | 2016-06-14 21:29:45 +0300 | [diff] [blame] | 24 | #include <linux/interrupt.h> |
| 25 | #include <linux/kernel.h> |
Paul Gortmaker | cc3ae7b | 2016-07-13 20:18:58 -0400 | [diff] [blame] | 26 | #include <linux/export.h> |
Andy Shevchenko | 5823d08 | 2016-06-14 21:29:45 +0300 | [diff] [blame] | 27 | #include <linux/mutex.h> |
| 28 | #include <linux/pci.h> |
| 29 | |
| 30 | #include <asm/intel-mid.h> |
| 31 | |
| 32 | /* Registers */ |
| 33 | #define PM_STS 0x00 |
| 34 | #define PM_CMD 0x04 |
| 35 | #define PM_ICS 0x08 |
| 36 | #define PM_WKC(x) (0x10 + (x) * 4) |
| 37 | #define PM_WKS(x) (0x18 + (x) * 4) |
| 38 | #define PM_SSC(x) (0x20 + (x) * 4) |
| 39 | #define PM_SSS(x) (0x30 + (x) * 4) |
| 40 | |
| 41 | /* Bits in PM_STS */ |
| 42 | #define PM_STS_BUSY (1 << 8) |
| 43 | |
| 44 | /* Bits in PM_CMD */ |
| 45 | #define PM_CMD_CMD(x) ((x) << 0) |
| 46 | #define PM_CMD_IOC (1 << 8) |
| 47 | #define PM_CMD_D3cold (1 << 21) |
| 48 | |
| 49 | /* List of commands */ |
| 50 | #define CMD_SET_CFG 0x01 |
| 51 | |
| 52 | /* Bits in PM_ICS */ |
| 53 | #define PM_ICS_INT_STATUS(x) ((x) & 0xff) |
| 54 | #define PM_ICS_IE (1 << 8) |
| 55 | #define PM_ICS_IP (1 << 9) |
| 56 | #define PM_ICS_SW_INT_STS (1 << 10) |
| 57 | |
| 58 | /* List of interrupts */ |
| 59 | #define INT_INVALID 0 |
| 60 | #define INT_CMD_COMPLETE 1 |
| 61 | #define INT_CMD_ERR 2 |
| 62 | #define INT_WAKE_EVENT 3 |
| 63 | #define INT_LSS_POWER_ERR 4 |
| 64 | #define INT_S0iX_MSG_ERR 5 |
| 65 | #define INT_NO_C6 6 |
| 66 | #define INT_TRIGGER_ERR 7 |
| 67 | #define INT_INACTIVITY 8 |
| 68 | |
| 69 | /* South Complex devices */ |
| 70 | #define LSS_MAX_SHARED_DEVS 4 |
| 71 | #define LSS_MAX_DEVS 64 |
| 72 | |
| 73 | #define LSS_WS_BITS 1 /* wake state width */ |
| 74 | #define LSS_PWS_BITS 2 /* power state width */ |
| 75 | |
| 76 | /* Supported device IDs */ |
Andy Shevchenko | ca22312 | 2016-07-05 23:09:08 +0300 | [diff] [blame] | 77 | #define PCI_DEVICE_ID_PENWELL 0x0828 |
Andy Shevchenko | 5823d08 | 2016-06-14 21:29:45 +0300 | [diff] [blame] | 78 | #define PCI_DEVICE_ID_TANGIER 0x11a1 |
| 79 | |
| 80 | struct mid_pwr_dev { |
| 81 | struct pci_dev *pdev; |
| 82 | pci_power_t state; |
| 83 | }; |
| 84 | |
| 85 | struct mid_pwr { |
| 86 | struct device *dev; |
| 87 | void __iomem *regs; |
| 88 | int irq; |
| 89 | bool available; |
| 90 | |
| 91 | struct mutex lock; |
| 92 | struct mid_pwr_dev lss[LSS_MAX_DEVS][LSS_MAX_SHARED_DEVS]; |
| 93 | }; |
| 94 | |
| 95 | static struct mid_pwr *midpwr; |
| 96 | |
| 97 | static u32 mid_pwr_get_state(struct mid_pwr *pwr, int reg) |
| 98 | { |
| 99 | return readl(pwr->regs + PM_SSS(reg)); |
| 100 | } |
| 101 | |
| 102 | static void mid_pwr_set_state(struct mid_pwr *pwr, int reg, u32 value) |
| 103 | { |
| 104 | writel(value, pwr->regs + PM_SSC(reg)); |
| 105 | } |
| 106 | |
| 107 | static void mid_pwr_set_wake(struct mid_pwr *pwr, int reg, u32 value) |
| 108 | { |
| 109 | writel(value, pwr->regs + PM_WKC(reg)); |
| 110 | } |
| 111 | |
| 112 | static void mid_pwr_interrupt_disable(struct mid_pwr *pwr) |
| 113 | { |
| 114 | writel(~PM_ICS_IE, pwr->regs + PM_ICS); |
| 115 | } |
| 116 | |
| 117 | static bool mid_pwr_is_busy(struct mid_pwr *pwr) |
| 118 | { |
| 119 | return !!(readl(pwr->regs + PM_STS) & PM_STS_BUSY); |
| 120 | } |
| 121 | |
| 122 | /* Wait 500ms that the latest PWRMU command finished */ |
| 123 | static int mid_pwr_wait(struct mid_pwr *pwr) |
| 124 | { |
| 125 | unsigned int count = 500000; |
| 126 | bool busy; |
| 127 | |
| 128 | do { |
| 129 | busy = mid_pwr_is_busy(pwr); |
| 130 | if (!busy) |
| 131 | return 0; |
| 132 | udelay(1); |
| 133 | } while (--count); |
| 134 | |
| 135 | return -EBUSY; |
| 136 | } |
| 137 | |
| 138 | static int mid_pwr_wait_for_cmd(struct mid_pwr *pwr, u8 cmd) |
| 139 | { |
| 140 | writel(PM_CMD_CMD(cmd), pwr->regs + PM_CMD); |
| 141 | return mid_pwr_wait(pwr); |
| 142 | } |
| 143 | |
| 144 | static int __update_power_state(struct mid_pwr *pwr, int reg, int bit, int new) |
| 145 | { |
| 146 | int curstate; |
| 147 | u32 power; |
| 148 | int ret; |
| 149 | |
| 150 | /* Check if the device is already in desired state */ |
| 151 | power = mid_pwr_get_state(pwr, reg); |
| 152 | curstate = (power >> bit) & 3; |
| 153 | if (curstate == new) |
| 154 | return 0; |
| 155 | |
| 156 | /* Update the power state */ |
| 157 | mid_pwr_set_state(pwr, reg, (power & ~(3 << bit)) | (new << bit)); |
| 158 | |
| 159 | /* Send command to SCU */ |
| 160 | ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG); |
| 161 | if (ret) |
| 162 | return ret; |
| 163 | |
| 164 | /* Check if the device is already in desired state */ |
| 165 | power = mid_pwr_get_state(pwr, reg); |
| 166 | curstate = (power >> bit) & 3; |
| 167 | if (curstate != new) |
| 168 | return -EAGAIN; |
| 169 | |
| 170 | return 0; |
| 171 | } |
| 172 | |
| 173 | static pci_power_t __find_weakest_power_state(struct mid_pwr_dev *lss, |
| 174 | struct pci_dev *pdev, |
| 175 | pci_power_t state) |
| 176 | { |
| 177 | pci_power_t weakest = PCI_D3hot; |
| 178 | unsigned int j; |
| 179 | |
| 180 | /* Find device in cache or first free cell */ |
| 181 | for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) { |
| 182 | if (lss[j].pdev == pdev || !lss[j].pdev) |
| 183 | break; |
| 184 | } |
| 185 | |
| 186 | /* Store the desired state in cache */ |
| 187 | if (j < LSS_MAX_SHARED_DEVS) { |
| 188 | lss[j].pdev = pdev; |
| 189 | lss[j].state = state; |
| 190 | } else { |
| 191 | dev_WARN(&pdev->dev, "No room for device in PWRMU LSS cache\n"); |
| 192 | weakest = state; |
| 193 | } |
| 194 | |
| 195 | /* Find the power state we may use */ |
| 196 | for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) { |
| 197 | if (lss[j].state < weakest) |
| 198 | weakest = lss[j].state; |
| 199 | } |
| 200 | |
| 201 | return weakest; |
| 202 | } |
| 203 | |
| 204 | static int __set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev, |
| 205 | pci_power_t state, int id, int reg, int bit) |
| 206 | { |
| 207 | const char *name; |
| 208 | int ret; |
| 209 | |
| 210 | state = __find_weakest_power_state(pwr->lss[id], pdev, state); |
| 211 | name = pci_power_name(state); |
| 212 | |
| 213 | ret = __update_power_state(pwr, reg, bit, (__force int)state); |
| 214 | if (ret) { |
| 215 | dev_warn(&pdev->dev, "Can't set power state %s: %d\n", name, ret); |
| 216 | return ret; |
| 217 | } |
| 218 | |
| 219 | dev_vdbg(&pdev->dev, "Set power state %s\n", name); |
| 220 | return 0; |
| 221 | } |
| 222 | |
| 223 | static int mid_pwr_set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev, |
| 224 | pci_power_t state) |
| 225 | { |
| 226 | int id, reg, bit; |
| 227 | int ret; |
| 228 | |
| 229 | id = intel_mid_pwr_get_lss_id(pdev); |
| 230 | if (id < 0) |
| 231 | return id; |
| 232 | |
| 233 | reg = (id * LSS_PWS_BITS) / 32; |
| 234 | bit = (id * LSS_PWS_BITS) % 32; |
| 235 | |
| 236 | /* We support states between PCI_D0 and PCI_D3hot */ |
| 237 | if (state < PCI_D0) |
| 238 | state = PCI_D0; |
| 239 | if (state > PCI_D3hot) |
| 240 | state = PCI_D3hot; |
| 241 | |
| 242 | mutex_lock(&pwr->lock); |
| 243 | ret = __set_power_state(pwr, pdev, state, id, reg, bit); |
| 244 | mutex_unlock(&pwr->lock); |
| 245 | return ret; |
| 246 | } |
| 247 | |
| 248 | int intel_mid_pci_set_power_state(struct pci_dev *pdev, pci_power_t state) |
| 249 | { |
| 250 | struct mid_pwr *pwr = midpwr; |
| 251 | int ret = 0; |
| 252 | |
| 253 | might_sleep(); |
| 254 | |
| 255 | if (pwr && pwr->available) |
| 256 | ret = mid_pwr_set_power_state(pwr, pdev, state); |
| 257 | dev_vdbg(&pdev->dev, "set_power_state() returns %d\n", ret); |
| 258 | |
| 259 | return 0; |
| 260 | } |
| 261 | EXPORT_SYMBOL_GPL(intel_mid_pci_set_power_state); |
| 262 | |
| 263 | int intel_mid_pwr_get_lss_id(struct pci_dev *pdev) |
| 264 | { |
| 265 | int vndr; |
| 266 | u8 id; |
| 267 | |
| 268 | /* |
| 269 | * Mapping to PWRMU index is kept in the Logical SubSystem ID byte of |
| 270 | * Vendor capability. |
| 271 | */ |
| 272 | vndr = pci_find_capability(pdev, PCI_CAP_ID_VNDR); |
| 273 | if (!vndr) |
| 274 | return -EINVAL; |
| 275 | |
| 276 | /* Read the Logical SubSystem ID byte */ |
| 277 | pci_read_config_byte(pdev, vndr + INTEL_MID_PWR_LSS_OFFSET, &id); |
| 278 | if (!(id & INTEL_MID_PWR_LSS_TYPE)) |
| 279 | return -ENODEV; |
| 280 | |
| 281 | id &= ~INTEL_MID_PWR_LSS_TYPE; |
| 282 | if (id >= LSS_MAX_DEVS) |
| 283 | return -ERANGE; |
| 284 | |
| 285 | return id; |
| 286 | } |
| 287 | |
| 288 | static irqreturn_t mid_pwr_irq_handler(int irq, void *dev_id) |
| 289 | { |
| 290 | struct mid_pwr *pwr = dev_id; |
| 291 | u32 ics; |
| 292 | |
| 293 | ics = readl(pwr->regs + PM_ICS); |
| 294 | if (!(ics & PM_ICS_IP)) |
| 295 | return IRQ_NONE; |
| 296 | |
| 297 | writel(ics | PM_ICS_IP, pwr->regs + PM_ICS); |
| 298 | |
| 299 | dev_warn(pwr->dev, "Unexpected IRQ: %#x\n", PM_ICS_INT_STATUS(ics)); |
| 300 | return IRQ_HANDLED; |
| 301 | } |
| 302 | |
| 303 | struct mid_pwr_device_info { |
| 304 | int (*set_initial_state)(struct mid_pwr *pwr); |
| 305 | }; |
| 306 | |
| 307 | static int mid_pwr_probe(struct pci_dev *pdev, const struct pci_device_id *id) |
| 308 | { |
| 309 | struct mid_pwr_device_info *info = (void *)id->driver_data; |
| 310 | struct device *dev = &pdev->dev; |
| 311 | struct mid_pwr *pwr; |
| 312 | int ret; |
| 313 | |
| 314 | ret = pcim_enable_device(pdev); |
| 315 | if (ret < 0) { |
| 316 | dev_err(&pdev->dev, "error: could not enable device\n"); |
| 317 | return ret; |
| 318 | } |
| 319 | |
| 320 | ret = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev)); |
| 321 | if (ret) { |
| 322 | dev_err(&pdev->dev, "I/O memory remapping failed\n"); |
| 323 | return ret; |
| 324 | } |
| 325 | |
| 326 | pwr = devm_kzalloc(dev, sizeof(*pwr), GFP_KERNEL); |
| 327 | if (!pwr) |
| 328 | return -ENOMEM; |
| 329 | |
| 330 | pwr->dev = dev; |
| 331 | pwr->regs = pcim_iomap_table(pdev)[0]; |
| 332 | pwr->irq = pdev->irq; |
| 333 | |
| 334 | mutex_init(&pwr->lock); |
| 335 | |
| 336 | /* Disable interrupts */ |
| 337 | mid_pwr_interrupt_disable(pwr); |
| 338 | |
| 339 | if (info && info->set_initial_state) { |
| 340 | ret = info->set_initial_state(pwr); |
| 341 | if (ret) |
| 342 | dev_warn(dev, "Can't set initial state: %d\n", ret); |
| 343 | } |
| 344 | |
| 345 | ret = devm_request_irq(dev, pdev->irq, mid_pwr_irq_handler, |
| 346 | IRQF_NO_SUSPEND, pci_name(pdev), pwr); |
| 347 | if (ret) |
| 348 | return ret; |
| 349 | |
| 350 | pwr->available = true; |
| 351 | midpwr = pwr; |
| 352 | |
| 353 | pci_set_drvdata(pdev, pwr); |
| 354 | return 0; |
| 355 | } |
| 356 | |
Andy Shevchenko | ca22312 | 2016-07-05 23:09:08 +0300 | [diff] [blame] | 357 | static int mid_set_initial_state(struct mid_pwr *pwr) |
Andy Shevchenko | 5823d08 | 2016-06-14 21:29:45 +0300 | [diff] [blame] | 358 | { |
| 359 | unsigned int i, j; |
| 360 | int ret; |
| 361 | |
| 362 | /* |
| 363 | * Enable wake events. |
| 364 | * |
| 365 | * PWRMU supports up to 32 sources for wake up the system. Ungate them |
| 366 | * all here. |
| 367 | */ |
| 368 | mid_pwr_set_wake(pwr, 0, 0xffffffff); |
| 369 | mid_pwr_set_wake(pwr, 1, 0xffffffff); |
| 370 | |
| 371 | /* |
| 372 | * Power off South Complex devices. |
| 373 | * |
| 374 | * There is a map (see a note below) of 64 devices with 2 bits per each |
| 375 | * on 32-bit HW registers. The following calls set all devices to one |
| 376 | * known initial state, i.e. PCI_D3hot. This is done in conjunction |
| 377 | * with PMCSR setting in arch/x86/pci/intel_mid_pci.c. |
| 378 | * |
| 379 | * NOTE: The actual device mapping is provided by a platform at run |
| 380 | * time using vendor capability of PCI configuration space. |
| 381 | */ |
| 382 | mid_pwr_set_state(pwr, 0, 0xffffffff); |
| 383 | mid_pwr_set_state(pwr, 1, 0xffffffff); |
| 384 | mid_pwr_set_state(pwr, 2, 0xffffffff); |
| 385 | mid_pwr_set_state(pwr, 3, 0xffffffff); |
| 386 | |
| 387 | /* Send command to SCU */ |
| 388 | ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG); |
| 389 | if (ret) |
| 390 | return ret; |
| 391 | |
| 392 | for (i = 0; i < LSS_MAX_DEVS; i++) { |
| 393 | for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) |
| 394 | pwr->lss[i][j].state = PCI_D3hot; |
| 395 | } |
| 396 | |
| 397 | return 0; |
| 398 | } |
| 399 | |
Andy Shevchenko | ca22312 | 2016-07-05 23:09:08 +0300 | [diff] [blame] | 400 | static const struct mid_pwr_device_info mid_info = { |
| 401 | .set_initial_state = mid_set_initial_state, |
Andy Shevchenko | 5823d08 | 2016-06-14 21:29:45 +0300 | [diff] [blame] | 402 | }; |
| 403 | |
| 404 | static const struct pci_device_id mid_pwr_pci_ids[] = { |
Andy Shevchenko | ca22312 | 2016-07-05 23:09:08 +0300 | [diff] [blame] | 405 | { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PENWELL), (kernel_ulong_t)&mid_info }, |
| 406 | { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_TANGIER), (kernel_ulong_t)&mid_info }, |
Andy Shevchenko | 5823d08 | 2016-06-14 21:29:45 +0300 | [diff] [blame] | 407 | {} |
| 408 | }; |
Andy Shevchenko | 5823d08 | 2016-06-14 21:29:45 +0300 | [diff] [blame] | 409 | |
| 410 | static struct pci_driver mid_pwr_pci_driver = { |
| 411 | .name = "intel_mid_pwr", |
| 412 | .probe = mid_pwr_probe, |
| 413 | .id_table = mid_pwr_pci_ids, |
| 414 | }; |
| 415 | |
| 416 | builtin_pci_driver(mid_pwr_pci_driver); |